The invention relates to a latching fitting for a vehicle seat for releasably locking two parts that can be moved relative to one another according to the preamble of claim 1, particularly for adjusting and locking a backrest part with respect to a seat part of the vehicle seat.
From DE 198 45 698 A1 a locking device for adjusting fittings on vehicle seats is known that comprises a latching area having a toothing and a latching member having a counter toothing, wherein the toothing and the counter toothing can be brought into and out of engagement and are lockable in an engagement position. In the engagement position the tooth heads of the toothing and counter toothing keep a distance between their apex and the corresponding tooth feet of the respective opposing elements, while the corresponding toothings butt against the tooth flanks. The tooth flanks are connected to the apex via a curved transition region starting at their head sided ends.
Under high loads, for instance in case of a crash, the danger exists that the latching toothing of the latching element connected to one of the parts gets out of engagement with the counter latching toothing of the locking piece connected to the other part. In order to provide, under perpetuation of the essential dimensions of the latching area and the latching member, a higher security of the locking in case of a crash by means of changing the tooth shape at the tooth head region alone, the connecting area lying at the end of the tooth flanks is displacedly arranged towards the tooth foot of the opposing element between the tooth flank and the transition region by means of a reduction of the transition radius, so that an enlargement of the tooth flank covering results while having unmodified toothing relations otherwise, which tooth flank covering keeps the toothing in engagement, even in case of the attack of higher loads that lead to a stronger deformation of the loaded parts.
From DE 101 23 800 A1 an inclination adjusting fitting for the backrest of a motor vehicle seat is known in case of which a first fitting part is firmly connected to the seat part and a second fitting part is connected to the backrest part, wherein the seat part and the backrest part are pivotably connected about a common pivoting axis and the backrest part is pivotably supported on the seat part about an axis running parallel to the pivoting axis and is secured in a latching position by means of a locking pawl, in which latching position a toothing of the second fitting part engages a counter toothing of the first fitting part. In order to design the inclination adjusting fitting in a crash-proof manner out of a few parts, so that the toothings being in engagement with each other are evenly loaded and stay in engagement even in case of a crash, the engagement angle of the tooth flanks absorbing load in case of a crash decreases at the toothing of the second fitting apart and at their complementary counter toothing with increasing distance to the axis of the second fitting apart running parallel to the pivoting axis.
In case of a latching fitting of the aforementioned kind it is essential that in the locking position of the latching fitting the engaged toothing and counter toothing of the latching member stay in engagement even in case of a crash, so that the mutual locking of seat and backrest part is guaranteed and the toothing engagement of the latching toothing into the counter latching toothing is as possible play-free, in order to guarantee a fixed relative position of the parts of the vehicle seat relatively movable and to avoid flapper sounds, particularly in case of an unoccupied vehicle seat.
The problem underlying the invention is to make the toothing engagement of the latching toothing into the counter latching toothing play-free and to avoid that the toothings of the latching toothing and the counter latching toothing are separated from one another in case of a crash.